The hardcover of this came out in 2012. The current kindle and, one assumes, the paperback edition include additional information written after the publication of the hardcover.
There's a whole genre of non-fiction out there where someone lines up a publisher for a book idea wherein the author will do ... something ... for a year and write about how that turned out/made them feel/what they learned. There's some amount of background research included, but it is more about personal reporting and personal experience than it is about conveying a detailed or comprehensive body of knowledge.
I have mixed feelings about this genre. In a way, it's my Very Favorite Kind of Non-Fiction, when it's something the author is really obsessed about and they write in an engaging way and they're really good (and somewhat brutal) at describing their feelings. Alas, because it is a Genre, there are more and more of these books where the author isn't actually all that obsessed and they don't come across as honest about their feeling experience or, worse, they come across as kind of judgy in a not-good way (there is judgy in a good way).
Wolman does a decent job. The goal was to not use/touch physical (paper or metal) money for a year. He does describe some incidents where that was Not Possible and how he dealt with that (notably, during the visit to India, he just got cash and spent cash). He recognizes that spending a year using only cash would likely have been much more difficult, but because he allowed his family to preserve some sense of privacy, we don't really get a sense of just how much his domestic arrangements helped him get around some of the need-cash moments. We only hear about the ones where an interview subject picks up the tab.
His background research was decent, and altho there were points where I felt he could have been a little more critical of his sources, he did spend a little time getting into whether people really carry around an average of $79 dollars.
Wolman started and ended the book in roughly the same place: paper and metal money will become increasingly marginalized, and that is a good thing. Traceability, when handled sensitively, can better balance individual and group values. For most of us, a loss of anonymity is already accepted, because we have switched so many of our payments to more traceable/less anonymous systems. He spent time talking to people who felt very strongly that paper and metal money should go away, and people who considered that part of End Times, and a variety in between; most seemed to believe even more strongly than him that cash was on its way out.
I wished at times that Wolman had framed his comparisons more explicitly as comparisons between payment systems, and did a more thorough exploration of how much various systems cost and who bore those costs. He got so wrapped up in seigniorage, that he only glancingly mentions the other costs borne by the government in producing paper and metal money -- he acknowledges that if you did a complete job of analyzing the costs, things would look a little different, but he never really gets into how the government's willingness to shoulder the cost of providing the worst kind of payment system (universal, small payments) is part of why cash hangs on: no one else would willingly take that burden on.
Because this was written/researched at a point in time when things looked particularly dire for the Euro, some of Wolman's commentary already seems a bit dated. However, he does recognize the trend towards regionalization of currency and does a nice job of sketching that trend. He even recognizes Krugman as being an strongly anomalous opponent, without letting that turn into a general attack on Krugman.
Wolman spends some time on specifically physical aspects of currency (wearing out, germs). I felt his analysis here was quite weak; it just felt like he was so grossed out by even touching the stuff, that he really couldn't bear to get into all the other disturbing things people do to/with currency (also, not once do those penny souvenir things get mentioned! For why?!? Probably his kid is/was too young to be in love with them yet).
All in all, an enjoyable read on an important subject, in which the author takes a relatively nuanced but non-neutral stance and defends it well. Worth your time but may not age well.